<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Title</title>
</head>
<body>
<script>
  // instanceof: 对象与构造函数在原型链上是否有关系
  function Aaa() {

  }

  let a1 = new Aaa();

  console.log(a1 instanceof Aaa);
</script>
</body>
</html>
